The 1884 Pittsburgh Alleghenys season was the third season of the Pittsburgh Alleghenys franchise.
The Alleghenys finished 11th in the American Association with a record of 30–78.
Note: G = Games played; AB = At bats; H = Hits; Avg.
= Batting average; HR = Home runs; RBI = Runs batted in
Note: G = Games pitched; IP = Innings pitched; W = Wins; L = Losses; ERA = Earned run average; SO = Strikeouts